Answer: Fourth root of 0.0016 is not a surd number (it is rational number).
If we know

, exponentiate number 10 times less:

And now we can use:

Now we take root from it:
![\sqrt[4]{0.2^(4)}](https://img.qammunity.org/2024/formulas/mathematics/high-school/tw2l0edfzkqkalofrqyvbe956t8h1wp5gy.png)
We can use formula:
![\sqrt[m]{a^(m)} = a](https://img.qammunity.org/2024/formulas/mathematics/high-school/ieso4ebj0pu6lsdta41wg4snayj7gwo6o0.png)
Replace values from formula:

And 0.2 is a rational number, so that number is not surd.
Hope this helps!